Thread-controlling device for sewing-machines



F. W. MERRICK.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JAN. 2. 1918.

5 j 3 g 4 4 Patented June 22, 1920.

2 SHEETSSHEET 1.

fizaenzaz" g w. SVKWJE F. W. MERRICK.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JAN.2. 191a.

Patented June 22, 1920.

Z SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.-

FRANK W. MERBICK, 0F BOSTON, MASSACHUSETTS.

THREAD-CONTROLLING DEVICE. non sswmemcm s,

Specification of LettersIate nt. P t t n 2 Application filed J'anuary 2, 1918. Serial No. 209,820;

v take-up device acts to take up the thread for the purpose of tightening a stitch.

In accordance with the invention, combine with a take-up, a thread-grip which holds the thread only during the pull of the take-up, and. releases the thread between stitches. 4 Y

A feature of the invention is that the release by the thread-controller takes place while the take-upstill holds the thread. That is to say, the grip releases the thread before the take-up relaxes, while the takeup is at or near its extreme extent.

The grip or look releases the thread independently of the stitch-making functions of the machine. The recovery of the take-up is timed to give up the thread as needed in forming the next stitch, so as to enable the thread to be drawn down for the passage of the; shuttle through a loop formed therein.

'The, foregoing feature's'of the invention make it possible to advance or otherwise shift the work between one stitch and the next without touching anything besidethe work itself. After the formation of a given stitch the thread may be pulled forward from the source of supply by hand,'if desired, adjacent theneedle. This enables me, if desired,to make the next succeeding stitch of any required length, as an inch-long stitch if that be wished. It also facilitates drawing forward a length of thread preparatory to beginning stitching.

More particularly, the invention is applicable in connection with thread-grip or thread-lock devices of the type brought into effective operation to grip or lockthe thread by the tension of the thread itself due to the draft produced by the action Ofthe take-up v ce i I The invention, in its preferred formof embodiment,combines with a thread-grip of lock device of the type just nmntioned a sition permittingthethread to render freely vpast'the grip or lo'ckdevice, and having combined with it means for causing it to take a working position in which the thread so acts upon the thread-grip 1 or thread-lock device, that the draft upon tlietl'iread operates the said device to check its own onfiow from the source of supply. Preferably, although not necessarily in all cases, the" movable threadcontroller is operatively controlled by' means of a continuously moving rotary actuator in the shape of-a cam. I

An illustrative embodiment of the invention, of the said preferred form, is shown in the drawings,in which latter,

Figure l is an elevation of certain parts of a straight-needle waxthread sewing machine, looking at the head-end thereof and movable thread-controller having an idlepo showing the I said illustrative embodiment and sufficient of the adjacent devices to render clear the relations, nature, and mode of operation of the parts, the thread-controller being shown in inoperative positionand the thread unlocked or ungripped.

F 2 is a partly sectional view of certain of'the parts shown in Fig. I, looking from theright-hand side in Fig. l.

Fig.3 is a view corresponding with 1 inthe main, but showing the partsin di er ent positions, with the thread-controller in operative position and the thread-grip or thread-lock closed upon the thread. I The drawings show various usual parts of a sewingmachine, including the upright 1 and horizontally extending arm 2 of the. main fixed part or gooseneck of the machine,

the head 3 at the outer end of said arm, the presser-bar 4 fitted to guides in the said head, the presser 5 carried by the presser-bar, the swinging feed-frame 6 hung by the pivot 7 to an upstanding ortion of the outer end of the said arm, t e awl-b'ar 8 working in guide-bearings in the said feed-frame, the awl 9 carried by the said awl-bar', the worksupport 10, the needle bar 11 working in guide-bearings in the post 12 adjacent the said work-support, the hooked needle 13 carried by the needle-bar and working upwardly from below, the swinging threadguidelt for carrying the thread around-the upraised needle and laying it within the open eye of the needle, underthe hook of and the operating shaft 16 rotating in bearings, one of which is shown in Fig. 2 at 17 in connection with upright 1 and arm 2. The drawings show also a well-known takeup device comprising a swing-arm 18 carrying a roll 19 adapted to travel in an are between two guide-rolls 20, 20, mounted upon pivots that are fixedly applied in connection with head 3. The said swing-arm is attached to a rockshaft 22, mounted in a bearing 23 applied to, the arm 2, the said rockshaft having combined therewith in practice means (not shown) connecting it operatively with the shaft 16 and arranged to operate to swing it from its advanced or idle position shown in Figs. 1 and 2, in which the thread a is left free between the two guide-rolls 20, 20, to its taking-up position in Fig. 3, in which the thread is extended around roll 19 in the form of a loop or bight drawn through between the said guide-rolls, and then swing it back to the position shown in Figs. 1 and 2 so as to render up the thread composing the said loop, and so on.

The thread-gi ip or lock device and threadcontroller are arranged in position to act upon the thread on its way from the source of supply to the first guide-roll 20 of the take-up. An ordinary form of thread-actuated thread-grip or lock device is shown, it comprising a lever 24 having a long arm furnished with a guidepassage at 25 for the thread, and a short arm 24 adapted to serve as a movable thread-clamping member in conjunction with an opposing thread-clamping member 26, which in this instance is a loosely-pivoted block. The thread passes through a guide 27 on one end of the pivoted clamping member 26, then between the arm 24 and the said member 26, then through the guide-passage 25 of the long arm of the lever 24, then through the opening or eye 30 of the controller 28, and thence to the guide-roll 20. The parts are so formed and arranged that when the thread follows its normal line of draft from guide 27 to roll 20 it does not act upon the long arm of lever 24 with any tendency to operate such lever to clamp the thread. Such action takes place only in consequence of the thread being deflected from such normal line by the action of the thread controller 28. The said thread-controller is shown as a lever that is pivotally mounted at 29 and provided with a guide-eye at 30, through which the thread passes after leaving the passage 25 of the long arm of the thread-clamping lever 24. For the actuation of the thread-controller I employ by preference a cam 31 carried by the shaft 16. This cam has a groovewithin which works a roll 32 carried by the thread controller. The said groove is sufficiently wide to permit some play of the controller. A contracting spiral spring 33 connected with the thread-controller operates with a tendency to turn the thread-controller on its pivot so as to keep the roll 32 in contact with the acting wall of the cam-groove. The cam is so shaped that normally it permits the thread-controller to occupy such a position that the thread extends in its normal path from guide 27 to roll 20, permitting the clamping members of the thread-gr1p or look device to remain apart so that the thread may render freely through in the direction of the work. This position is represented in Figs. 1 and 2. The portion of the cam which calls the thread-controller into action to bring about the clamping action operates positively. to turn the thread-controller upon its pivot into the position shown in Fig. 3 so as to deflect the thread out of its normal path at a point between guide 27 and roll 20. This movement of the thread-controller is accompanied or followed by move; ment of take-up arm 18 into its position in Fig. 3, with the result that thetension of the thread due to the draft produced by the taking-up action acts upon the long arm of lever 24 in manner to close the clamping portion 24 of such lever toward and against the opposing clamping member 26, so as to clamp the thread firmly between the take-up and the source of supply.

Briefly stated, the cam controls the move ments of the thread-controller into its idle position and its working or thread-deflecting position, respectively, and in the latter (working or thread-deflecting) position of the thread-controller the thread-grip or look device is made effective by the tension due to the pull on the thread to check the delivery of the thread from the source of supply, while in the former (idle) position the thread-grip or look device is inoperative by the pull of the thread.

, As previously indicated herein the thread: controller is operated with such timing as to bring about a release of the grip upon the thread between successive stitches, so that the work may be turned within the machine, or be withdrawn, without it being a thread, and then into a position permitting the thread to render freely past the grip or look.

2. In thread-controlling. devices, the combination with a take-up and a thread-operated thread-grip or look, of a movable threadcontroller, and a cam controlling the thread-controller so as to have move operates the thread-grip or lock to check the thread at the supply side, and then into a position permitting the thread to render freely past.

3. In thread-controlling devices, the combination with a take-up, and a thread-grip or thread-lock device adapted to be brought into effective operation to grip or lock the thread by tension of the thread itself, of a movable thread-controller, and means giving the same automatically a position causing the thread to act upon the thread-grip or thread-lock device so that taking-up draft acting in substantially the normal line of travel of the thread operates the latter device to check the thread and then a position permitting the thread to render freely past the grip or lock, the said take-up timedto give up thread as needed in forming the next stitch.

4. In thread-controlling devices, the combination with a take-up, a thread-operated thread-grip or lock and a thread-guide occupying a stationary position, of a movable thread-controller engaging with the thread between said thread-grip or lock and said guide, and a cam controlling the movements of the thread-controller into a Working or thread-defiecting position in which the pull onthe thread due to the action of the takeup in tightening the stitch operates the thread-grip or lock tocheck the thread, and

then, into a position permitting the thread to render freely past, the said take-up timed to give up thread as needed in forming the next stitch.

5. In thread-controlling devices, in combination, a take-up, and thread-gripping means constructed and operating to hold the thread during the taking-up action and to release the thread before the 'take-up i gives up slack.

6. In thread-controlling devices, in combination, a take-up, a thread-grip adapted to be actuated by the tension of the thread, and a thread-controller acting through the thread to cause the thread to be gripped during the taking-up action and to be released While the take-up still holds the slack.

7. In thread-controlling devices for sewing machines, in combination, a take-up,

and a thread-grip operated to hold the tween stitches.

In testimony whereof I aflix my signature in presence of two Witnesses.

CHAS. F. RANDALL, ELLEN 0. SPRING. 

